# 注意到consumer函数是一个generator（生成器）:
# 任何包含yield关键字的函数都会自动成为生成器(generator)对象
def consumer():r = ''while True:# 3、consumer通过yield拿到消息，处理，又通过yield把结果传回；#    yield指令具有return关键字的作用。然后函数的堆栈会自动冻结(freeze)在这一行。#    当函数调用者的下一次利用next()或generator.send()或for-in来再次调用该函数时，#    就会从yield代码的下一行开始，继续执行，再返回下一次迭代结果。通过这种方式，迭代器可以实现无限序列和惰性求值。n = yield rif not n:returnprint('[CONSUMER] ←← Consuming %s...' % n)time.sleep(1)r = '200 OK'def produce():# 1、首先调用c.next()启动生成器c = consumer()next(c)n = 0while n < 5:n = n + 1print('[PRODUCER] →→ Producing %s...' % n)# 2、然后，一旦生产了东西，通过c.send(n)切换到consumer执行；cr = c.send(n)# 4、produce拿到consumer处理的结果，继续生产下一条消息；print('[PRODUCER] Consumer return: %s' % cr)# 5、produce决定不生产了，通过c.close()关闭consumer，整个过程结束。
    c.close()if __name__ == '__main__':start_time = time.time()# 6、整个流程无锁，由一个线程执行，produce和consumer协作完成任务，所以称为“协程”，在一个线程里协作完成。res = produce()# consumer(res)end_time = time.time()print(end_time-start_time)

def produce():n = 0res = []while n < 5:n = n + 1print('[PRODUCER] →→ Producing %s...' % n)res.append(n)return resdef consumer(res):passif __name__ == '__main__':start_time = time.time()# 6、整个流程无锁，由一个线程执行，produce和consumer协作完成任务，所以称为“协程”，在一个线程里协作完成。res = produce()consumer(res)end_time = time.time()print(end_time-start_time)

from greenlet import greenletdef eat(name):print('%s is eating 1'%name)gr2.switch('zhanwu')print('%s is eating 2' % name)gr2.switch()def play(name):print('%s is playing 1' % name)gr1.switch()print('%s is playing 2' % name)gr1 = greenlet(eat)
gr2 = greenlet(play)
gr1.switch('egon')  #切换的时候传参

from gevent import monkey
monkey.patch_all()   #将下面的阻塞操作变为非阻塞操作，这是用gevent必须的

def eat(name):print('%s is eating 1'%name)gevent.sleep(3)print('%s is eating 2' % name)def play(name):print('%s is playing 1' % name)gevent.sleep(4)print('%s is playing 2' % name)gevent.joinall([gevent.spawn(eat,'egon'),gevent.spawn(play,'egon')]
)

如果开多个进程，每个进程里开多个线程，每个线程里再开协程，会大大提升效率。server端
from gevent import monkey,spawn;monkey.patch_all()
from socket import *def talk(conn):while True:try:data = conn.recv(1024)if not data: breakconn.send(data.upper())except ConnectionResetError:breakconn.close()def server(ip,port): # 来一个客户端，起一个connserver = socket(AF_INET, SOCK_STREAM)server.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)server.bind((ip, port))server.listen(5)while True:conn,addr = server.accept()spawn(talk,conn)server.close()if __name__ == '__main__':g = spawn(server,'127.0.0.1',8087)g.join()client端：
from socket import *
from threading import Thread,currentThread
def client():client = socket(AF_INET, SOCK_STREAM)client.connect(('127.0.0.1',8087))while True:client.send(('%s say hello'%currentThread().getName()).encode('utf8'))data = client.recv(1024)print(data.decode('utf-8'))if __name__ == '__main__':for i in range(500):t = Thread(target=client)t.start()